An air battery is a battery adopting oxygen as a cathode active material; and at the time of discharge, it takes in an oxygen-containing gas from the outside. As such, it is possible to have a larger proportion of an anode active material in the battery case, compared with other types of batteries comprising cathode and anode active materials therein. Accordingly, in principle the air battery is characterized to have a large dischargeable electric capacity and to be easily reduced in size and weight. Further, since oxygen to be employed as the cathode active material has a strong oxidation power, the electromotive force of the battery is relatively high. Moreover, oxygen is characterized to be a clean resource whose amount is not limited, and therefore the air battery is environmentally-friendly. The air battery with many advantages in this way is expected to be used for hybrid vehicles, portable appliances etc., and the high performance of the air battery is demanded these days.
As a technique related to such an air battery, Patent Document 1 for example discloses a battery cell comprising a lithium anode, non-aqueous electrolyte, solid electrolyte, aqueous electrolyte, and cathode.